The Webb Telescope Observes an Unusual Set of Nested Dust Rings in Space

() — A new image from the James Webb Space Telescope shows rings of dust plumes created by violent interactions between two stars.

The image is part of new research revealing how intense starlight can push matter out into space, focusing on a binary star system located 5,000 light-years from Earth in the constellation Cygnus.

The star system, called WR140, includes a Wolf-Rayet star and a blue supergiant that revolve around each other in an orbit that takes eight years to complete. The blue supergiant is an O-type star, one of the most massive star types known. Only a few massive stars evolve into a Wolf-Rayet as they near the end of their life cycles. This stage lasts a few hundred thousand years.

Astronomers have been observing this binary star system for two decades from the WM Keck Observatory in Hawaii.

Every eight years, as stars approach each other, they release plumes of dust that stretch thousands of times the distance between Earth and the Sun. The researchers observed the plumes to measure how starlight can impact matter for its study published this Wednesday in the academic journal Nature.

Light can exert a type of push called radiation pressure on matter, but it’s hard to detect in space.

“It’s hard to see that starlight causes acceleration because the force vanishes with distance, and other forces quickly take over,” said the study’s first author, Yinuo Han, a doctoral student at the Institute of Astronomy of the University of China. University of Cambridge, in the United Kingdom, in a statement.

“To witness the acceleration to the level that it becomes measurable, the material has to be reasonably close to the star or the source of the radiation pressure has to be extra strong.” WR140 is a binary star whose fierce radiation field overwhelms these effects, putting them within reach of our high-precision data.”

All stars generate their own stellar wind, or streams of gas expelled into space, but massive Wolf-Rayet stars can whip up the winds in something more like a stellar hurricane. Wolf-Rayet stars, in the later stages of their life cycle, have shed their hydrogen shell. Hydrogen cannot form dust by itself, but other elements located inside a star, such as carbon, can.

The carbon condenses into soot dust in the fast swirling wind, which glows with infrared light invisible to the human eye. But telescopes can detect this bright, warm light.

The team’s observations revealed that the dust plumes form where stellar winds from the two giant stars collide, creating a cone-shaped shock front between the stars.

As the stars pass through their oval orbit, the shock front also shifts, causing the smoke-like dust plume to spiral. If stars had a circular orbit, a whirlpool would form. Instead, the oval orbit creates delays in dust production that make the dust plumes resemble rings or shells.

The end result resembles an irregular target or something that looks like a spider’s web.

The Webb Telescope was able to peer much deeper into the binary star system than ground-based telescopes and observed nearly 20 accelerating plumes of dust nested within one another.

“There seemed to be a strange diffraction pattern, and I was concerned that it was a visual effect created by the extreme brightness of the stars,” said study author Ryan Lau, principal investigator for the Webb Early Release Science program and an assistant astronomer at the NOIRLab of the National Science Foundation, in a NASA statement.

“However, as soon as I downloaded the final data I realized I wasn’t seeing a diffraction pattern, but rather dust rings surrounding WR 140, at least 17 of them.”

The journal nature astronomy published this Wednesday the results of the observation of the Webb.

“Like clockwork, this star blows out sculpted smoke rings every eight years, with all this wonderful physics written on it that then billows in the wind like a banner for us to read,” said study co-author Peter Tuthill, professor of the University of Sydney School of Physics, in a statement.

“Eight years later, when the binary system returns to its orbit, another one appears just like the previous one, going out into space inside the bubble of the previous one, like a nested set of giant Russian dolls.”

The predictable production of a plume of dust every eight years in the star system provided researchers with the perfect target to study the rate of expansion of each dust spiral. Instead of expanding at a constant rate, they were observed to speed up.

“In a sense, we always knew this must be the reason for the outflow, but I never dreamed we’d be able to see physics at work in this way,” Tuthill said. “When I look at the data now, I see WR140’s plume unfurling like a giant sail made of dust. As it catches the wind of photons coming off the star, like a yacht catching a gust, it makes a sudden leap forward.”

Webb’s sensitivity will allow astronomers to make more observations of Wolf-Rayet stars and their intriguing physics in the future, according to the study authors.